DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

M66 Spontaneous rupture of synovium and tendon

  • Header · not billable

M66 is not billable. The category heads 103 billable codes in FY2027, grouped under 6 subdivisions.

Index → code

  • Rupture, rupturedsynovium (cyst) → M66.10
  • Rupture, rupturedsynovium (cyst)toe → M66.17-
  • Rupture, rupturedsynovium (cyst)foot → M66.17-

Where it sits

  1. Chapter 13 Diseases of the musculoskeletal system and connective tissue (M00-M99)
  2. M65-M67 Disorders of synovium and tendon (M65-M67)
  3. M66 Spontaneous rupture of synovium and tendon
Billable codes
103
Subdivisions
6
CC / MCC codes
0 / 0
HCC V28 codes
0
New FY2027
0
Index entries
52

Codes in M66

  1. M66.0
    Rupture of popliteal cyst
    Billable
  2. M66.1
    Rupture of synovium
    Header
    Inclusion terms 1, Excludes2 1

    Inclusion terms

    • Rupture of synovial cyst

    Excludes2

    • rupture of popliteal cyst (M66.0) M66.0
  3. M66.10
    Rupture of synovium, unspecified joint
    Billable
  4. M66.11
    Rupture of synovium, shoulder
    Header
  5. M66.111
    Rupture of synovium, right shoulder
    Billable
  6. M66.112
    Rupture of synovium, left shoulder
    Billable
  7. M66.119
    Rupture of synovium, unspecified shoulder
    Billable
  8. M66.12
    Rupture of synovium, elbow
    Header
  9. M66.121
    Rupture of synovium, right elbow
    Billable
  10. M66.122
    Rupture of synovium, left elbow
    Billable
  11. M66.129
    Rupture of synovium, unspecified elbow
    Billable
  12. M66.13
    Rupture of synovium, wrist
    Header
  13. M66.131
    Rupture of synovium, right wrist
    Billable
  14. M66.132
    Rupture of synovium, left wrist
    Billable
  15. M66.139
    Rupture of synovium, unspecified wrist
    Billable
  16. M66.14
    Rupture of synovium, hand and fingers
    Header
  17. M66.141
    Rupture of synovium, right hand
    Billable
  18. M66.142
    Rupture of synovium, left hand
    Billable
  19. M66.143
    Rupture of synovium, unspecified hand
    Billable
  20. M66.144
    Rupture of synovium, right finger(s)
    Billable
  21. M66.145
    Rupture of synovium, left finger(s)
    Billable
  22. M66.146
    Rupture of synovium, unspecified finger(s)
    Billable
  23. M66.15
    Rupture of synovium, hip
    Header
  24. M66.151
    Rupture of synovium, right hip
    Billable
  25. M66.152
    Rupture of synovium, left hip
    Billable
  26. M66.159
    Rupture of synovium, unspecified hip
    Billable
  27. M66.17
    Rupture of synovium, ankle, foot and toes
    Header
  28. M66.171
    Rupture of synovium, right ankle
    Billable
  29. M66.172
    Rupture of synovium, left ankle
    Billable
  30. M66.173
    Rupture of synovium, unspecified ankle
    Billable
  31. M66.174
    Rupture of synovium, right foot
    Billable
  32. M66.175
    Rupture of synovium, left foot
    Billable
  33. M66.176
    Rupture of synovium, unspecified foot
    Billable
  34. M66.177
    Rupture of synovium, right toe(s)
    Billable
  35. M66.178
    Rupture of synovium, left toe(s)
    Billable
  36. M66.179
    Rupture of synovium, unspecified toe(s)
    Billable
  37. M66.18
    Rupture of synovium, other site
    Billable
  38. M66.2
    Spontaneous rupture of extensor tendons
    Header
  39. M66.20
    Spontaneous rupture of extensor tendons, unspecified site
    Billable
  40. M66.21
    Spontaneous rupture of extensor tendons, shoulder
    Header
  41. M66.211
    Spontaneous rupture of extensor tendons, right shoulder
    Billable
  42. M66.212
    Spontaneous rupture of extensor tendons, left shoulder
    Billable
  43. M66.219
    Spontaneous rupture of extensor tendons, unspecified shoulder
    Billable
  44. M66.22
    Spontaneous rupture of extensor tendons, upper arm
    Header
  45. M66.221
    Spontaneous rupture of extensor tendons, right upper arm
    Billable
  46. M66.222
    Spontaneous rupture of extensor tendons, left upper arm
    Billable
  47. M66.229
    Spontaneous rupture of extensor tendons, unspecified upper arm
    Billable
  48. M66.23
    Spontaneous rupture of extensor tendons, forearm
    Header
  49. M66.231
    Spontaneous rupture of extensor tendons, right forearm
    Billable
  50. M66.232
    Spontaneous rupture of extensor tendons, left forearm
    Billable
  51. M66.239
    Spontaneous rupture of extensor tendons, unspecified forearm
    Billable
  52. M66.24
    Spontaneous rupture of extensor tendons, hand
    Header
  53. M66.241
    Spontaneous rupture of extensor tendons, right hand
    Billable
  54. M66.242
    Spontaneous rupture of extensor tendons, left hand
    Billable
  55. M66.249
    Spontaneous rupture of extensor tendons, unspecified hand
    Billable
  56. M66.25
    Spontaneous rupture of extensor tendons, thigh
    Header
  57. M66.251
    Spontaneous rupture of extensor tendons, right thigh
    Billable
  58. M66.252
    Spontaneous rupture of extensor tendons, left thigh
    Billable
  59. M66.259
    Spontaneous rupture of extensor tendons, unspecified thigh
    Billable
  60. M66.26
    Spontaneous rupture of extensor tendons, lower leg
    Header
  61. M66.261
    Spontaneous rupture of extensor tendons, right lower leg
    Billable
  62. M66.262
    Spontaneous rupture of extensor tendons, left lower leg
    Billable
  63. M66.269
    Spontaneous rupture of extensor tendons, unspecified lower leg
    Billable
  64. M66.27
    Spontaneous rupture of extensor tendons, ankle and foot
    Header
  65. M66.271
    Spontaneous rupture of extensor tendons, right ankle and foot
    Billable
  66. M66.272
    Spontaneous rupture of extensor tendons, left ankle and foot
    Billable
  67. M66.279
    Spontaneous rupture of extensor tendons, unspecified ankle and foot
    Billable
  68. M66.28
    Spontaneous rupture of extensor tendons, other site
    Billable
  69. M66.29
    Spontaneous rupture of extensor tendons, multiple sites
    Billable
  70. M66.3
    Spontaneous rupture of flexor tendons
    Header
  71. M66.30
    Spontaneous rupture of flexor tendons, unspecified site
    Billable
  72. M66.31
    Spontaneous rupture of flexor tendons, shoulder
    Header
  73. M66.311
    Spontaneous rupture of flexor tendons, right shoulder
    Billable
  74. M66.312
    Spontaneous rupture of flexor tendons, left shoulder
    Billable
  75. M66.319
    Spontaneous rupture of flexor tendons, unspecified shoulder
    Billable
  76. M66.32
    Spontaneous rupture of flexor tendons, upper arm
    Header
  77. M66.321
    Spontaneous rupture of flexor tendons, right upper arm
    Billable
  78. M66.322
    Spontaneous rupture of flexor tendons, left upper arm
    Billable
  79. M66.329
    Spontaneous rupture of flexor tendons, unspecified upper arm
    Billable
  80. M66.33
    Spontaneous rupture of flexor tendons, forearm
    Header
  81. M66.331
    Spontaneous rupture of flexor tendons, right forearm
    Billable
  82. M66.332
    Spontaneous rupture of flexor tendons, left forearm
    Billable
  83. M66.339
    Spontaneous rupture of flexor tendons, unspecified forearm
    Billable
  84. M66.34
    Spontaneous rupture of flexor tendons, hand
    Header
  85. M66.341
    Spontaneous rupture of flexor tendons, right hand
    Billable
  86. M66.342
    Spontaneous rupture of flexor tendons, left hand
    Billable
  87. M66.349
    Spontaneous rupture of flexor tendons, unspecified hand
    Billable
  88. M66.35
    Spontaneous rupture of flexor tendons, thigh
    Header
  89. M66.351
    Spontaneous rupture of flexor tendons, right thigh
    Billable
  90. M66.352
    Spontaneous rupture of flexor tendons, left thigh
    Billable
  91. M66.359
    Spontaneous rupture of flexor tendons, unspecified thigh
    Billable
  92. M66.36
    Spontaneous rupture of flexor tendons, lower leg
    Header
  93. M66.361
    Spontaneous rupture of flexor tendons, right lower leg
    Billable
  94. M66.362
    Spontaneous rupture of flexor tendons, left lower leg
    Billable
  95. M66.369
    Spontaneous rupture of flexor tendons, unspecified lower leg
    Billable
  96. M66.37
    Spontaneous rupture of flexor tendons, ankle and foot
    Header
  97. M66.371
    Spontaneous rupture of flexor tendons, right ankle and foot
    Billable
  98. M66.372
    Spontaneous rupture of flexor tendons, left ankle and foot
    Billable
  99. M66.379
    Spontaneous rupture of flexor tendons, unspecified ankle and foot
    Billable
  100. M66.38
    Spontaneous rupture of flexor tendons, other site
    Billable
  101. M66.39
    Spontaneous rupture of flexor tendons, multiple sites
    Billable
  102. M66.8
    Spontaneous rupture of other tendons
    Header
  103. M66.80
    Spontaneous rupture of other tendons, unspecified site
    Billable
  104. M66.81
    Spontaneous rupture of other tendons, shoulder
    Header
  105. M66.811
    Spontaneous rupture of other tendons, right shoulder
    Billable
  106. M66.812
    Spontaneous rupture of other tendons, left shoulder
    Billable
  107. M66.819
    Spontaneous rupture of other tendons, unspecified shoulder
    Billable
  108. M66.82
    Spontaneous rupture of other tendons, upper arm
    Header
  109. M66.821
    Spontaneous rupture of other tendons, right upper arm
    Billable
  110. M66.822
    Spontaneous rupture of other tendons, left upper arm
    Billable
  111. M66.829
    Spontaneous rupture of other tendons, unspecified upper arm
    Billable
  112. M66.83
    Spontaneous rupture of other tendons, forearm
    Header
  113. M66.831
    Spontaneous rupture of other tendons, right forearm
    Billable
  114. M66.832
    Spontaneous rupture of other tendons, left forearm
    Billable
  115. M66.839
    Spontaneous rupture of other tendons, unspecified forearm
    Billable
  116. M66.84
    Spontaneous rupture of other tendons, hand
    Header
  117. M66.841
    Spontaneous rupture of other tendons, right hand
    Billable
  118. M66.842
    Spontaneous rupture of other tendons, left hand
    Billable
  119. M66.849
    Spontaneous rupture of other tendons, unspecified hand
    Billable
  120. M66.85
    Spontaneous rupture of other tendons, thigh
    Header
  121. M66.851
    Spontaneous rupture of other tendons, right thigh
    Billable
  122. M66.852
    Spontaneous rupture of other tendons, left thigh
    Billable
  123. M66.859
    Spontaneous rupture of other tendons, unspecified thigh
    Billable
  124. M66.86
    Spontaneous rupture of other tendons, lower leg
    Header
  125. M66.861
    Spontaneous rupture of other tendons, right lower leg
    Billable
  126. M66.862
    Spontaneous rupture of other tendons, left lower leg
    Billable
  127. M66.869
    Spontaneous rupture of other tendons, unspecified lower leg
    Billable
  128. M66.87
    Spontaneous rupture of other tendons, ankle and foot
    Header
  129. M66.871
    Spontaneous rupture of other tendons, right ankle and foot
    Billable
  130. M66.872
    Spontaneous rupture of other tendons, left ankle and foot
    Billable
  131. M66.879
    Spontaneous rupture of other tendons, unspecified ankle and foot
    Billable
  132. M66.88
    Spontaneous rupture of other tendons, other sites
    Billable
  133. M66.89
    Spontaneous rupture of other tendons, multiple sites
    Billable
  134. M66.9
    Spontaneous rupture of unspecified tendon
    Billable
    Inclusion terms 1

    Inclusion terms

    • Rupture at musculotendinous junction, nontraumatic

Sources of each column.

Instructions

At M66

Includes

  • rupture that occurs when a normal force is applied to tissues that are inferred to have less than normal strength

Excludes2

  • rotator cuff syndrome (M75.1-) M75.1
  • rupture where an abnormal force is applied to normal tissue - see injury of tendon by body region

Notes that also apply

Chapter 13 instructions (Notes 1, Excludes2 10): printed on the chapter 13 page.

Index entries

  • Rupture, rupturedsynovium (cyst) → M66.10
  • Cyst (colloid) (mucous) (simple) (retention)Baker'sruptured → M66.0
  • Rupture, rupturedsynovium (cyst)shoulder region → M66.11-
  • Rupture, rupturedsynovium (cyst)elbow → M66.12-
  • Rupture, rupturedsynovium (cyst)upper arm → M66.12-
  • Rupture, rupturedsynovium (cyst)forearm → M66.13-
  • Rupture, rupturedsynovium (cyst)wrist → M66.13-
  • Rupture, rupturedsynovium (cyst)finger → M66.14-
  • Rupture, rupturedsynovium (cyst)hand → M66.14-
  • Rupture, rupturedsynovium (cyst)pelvic region → M66.15-
  • Rupture, rupturedsynovium (cyst)thigh → M66.15-
  • Rupture, rupturedsynovium (cyst)ankle → M66.17-
  • Rupture, rupturedsynovium (cyst)foot → M66.17-
  • Rupture, rupturedsynovium (cyst)toe → M66.17-
  • Rupture, rupturedsynovium (cyst)specified site NEC → M66.18
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous) → M66.9
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensor → M66.20
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)flexor → M66.30
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)shoulder region → M66.81-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)upper arm → M66.82-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)forearm → M66.83-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)hand → M66.84-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)pelvic region → M66.85-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)thigh → M66.85-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)lower leg → M66.86-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)ankle → M66.87-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)foot → M66.87-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)multiple sites → M66.89
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensorshoulder region → M66.21-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensorupper arm → M66.22-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensorforearm → M66.23-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensorhand → M66.24-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensorpelvic region → M66.25-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensorthigh → M66.25-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensorlower leg → M66.26-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensorankle → M66.27-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensorfoot → M66.27-
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensorspecified site NEC → M66.28
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)extensormultiple sites → M66.29
  • Rupture, rupturedtendon (traumatic)nontraumatic (spontaneous)flexorshoulder region → M66.31-

12 more, longer entries are not listed; the search box finds them by word.

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